Filter bottom microtiter plates are widely used in conjunction with various synthesis, production and analytical processes. An illustrative filter bottom microtiter plate 100 depicted in FIG. 1 includes a plurality of "bottomless" wells 102, one of which is shown. A filter 106 is disposed within each well 102 near a lower end 104. A flexible seal 108 having a capillary-sized opening 110 (i.e., about 200 microns) depends from lower end 104.
When filter bottom microtiter plate 100 is stationary or static, the filter 106/flexible seal 108 within each well 102 is capable of retaining both a resin 112, such as a 50-1000 micron solid support as is often used for solid-phase synthesis, and a liquid 114. Under acceleration, such as when filter bottom microtiter plate 100 is centrifuged, filter 106/flexible seal 108 pass liquid 114 but retain resin 112.
Filter bottom microtiter plates have been used in conjunction with solid-phase synthesis methods. Solid-phase synthesis involves linking a first chemical "base structure" molecule to a solid support media and subsequently adding, seriatim, chemical building blocks, or, alternatively, effecting chemical structural changes to the base structure (e.g., ring opening or closing). The base structure molecule participates in one or more reaction steps with the added chemical building blocks. Chemical compounds derived from the base structure molecule are thereby generated.
Each chemical compound, and its base structure molecule precursor, is typically attached to the solid support media via a cleavable linker that covalently links the chemical compound to the support media. For assay purposes, the various chemical compounds are usually removed from the support media. Such removal is accomplished by cleaving the linker, such as by exposure to long-wave ultraviolet light. The cleaved chemical compounds are typically eluted into a solvent that is recovered.
The elution operation may be carried out in wells 102 of filter bottom microtiter plate 100. To separate liquid 114 (e.g., solvent) from the solid support media 112, plate 100 is accelerated, such as by centrifuging. Such acceleration drives liquid 114 through filter 106/flexible seal 108. The solid support media is retained by the filter.
While filter bottom microtiter plate 100 provides satisfactory performance, it has a relatively complex structure. Such complexity is reflected in the cost of such plate, which can reach $10.00 per plate. The art would thus benefit from a simpler filter plate design that is less costly to implement.